Environmental Statement - Maersk Oil

Balloch Field Development Environmental Statement
Section 5 Assessment of Potential Impacts and Controls
Figure 5‐1 Sound Pressure Level plot for installation of a 600 mm pile at a manifold out to a distance of 30 km.
The majority of the energy within a piling pulse is contained within the low frequency components
2 kHz) have fallen below the normal background levels of
noise, whereas the lower frequency components are still above ambient noise levels. This suggests
that the piling signal for the cooling spool could be detected beyond a distance of 30 km (Figure 5‐2).
It should be noted that prevailing ambient noise levels and weather conditions could influence the
degree to which the sound could propagate (travel) through the water column.
Figure 5‐2 Frequency output profiles for piling sound at source (1 m) and 30 km.
Sound level dB
270
220
170
120
70
20
10 100 1000 10000 100000
Frequency Hz
Predicted noise level
Piling Source Level
Ambient Noise
5 ‐ 17